[root@cent Data_muning_perl]# perl -w ./Data_muning1.pl <cd.txt Use of uninitialized value $year in hash element at ./Data_muning1.pl line 11, <STDIN> line 1. Use of uninitialized value $year in hash element at ./Data_muning1.pl line 11, <STDIN> line 2. Use of uninitialized value $year in hash element at ./Data_muning1.pl line 11, <STDIN> line 3. Use of uninitialized value $year in hash element at ./Data_muning1.pl line 11, <STDIN> line 4. Use of uninitialized value $year in hash element at ./Data_muning1.pl line 11, <STDIN> line 5. Use of uninitialized value $year in hash element at ./Data_muning1.pl line 11, <STDIN> line 6. Use of uninitialized value $year in hash element at ./Data_muning1.pl line 11, <STDIN> line 7. Use of uninitialized value $year in hash element at ./Data_muning1.pl line 11, <STDIN> line 8. Use of uninitialized value $year in hash element at ./Data_muning1.pl line 11, <STDIN> line 9. Use of uninitialized value $year in hash element at ./Data_muning1.pl line 11, <STDIN> line 10. Use of uninitialized value $year in hash element at ./Data_muning1.pl line 11, <STDIN> line 11. Use of uninitialized value $year in hash element at ./Data_muning1.pl line 11, <STDIN> line 12. Use of uninitialized value $year in hash element at ./Data_muning1.pl line 11, <STDIN> line 13. In , 13 Cds were released. [root@cent Data_muning_perl]#